Watermark an image using OpenCV 2 and python.

watermark_image.py

import cv2

# Read in the image
image_file = 'original.jpg'
image = cv2.imread(image_file)
overlay = image.copy()
output = image.copy()
height, width = image.shape[:2]

# Stamp the image lower right corner and write it
alpha = 0.3
namestamp = "My Name"
cv2.putText(overlay, namestamp.format(alpha), (width-400, height-24), cv2.FONT_HERSHEY_PLAIN, 1.5, (255,255,255), thickness=2)
cv2.addWeighted(overlay, alpha, output, 1 - alpha, 0, output)
cv2.imwrite("stamped.jpg", output)